1. Field of the Invention
This invention relates to stereoscopic display methodologies and systems. More particularly, this invention relates to page flipping stereoscopic display methodologies and systems as well as apparatus used therein.
2. State of the Art
Stereoscopic display systems display two perspective images in such a way that each eye of the observer sees only one of the two images. There are many systems in existence that provide this capability through various methods. One of these methods in commonly referred to as “page flipping” or frame-sequential stereo video. In such methods, left and right perspective images are time-division multiplexed and thus displayed during different display periods (i.e., left and right perspective image display periods). Stereoscopic glasses (e.g., shutter-type or polarization-type glasses) are used to ensure that the left perspective images are presented to the left eye during the left perspective image display periods and that the right perspective images are presented to the right eye during the right perspective image display periods.
Autostereoscopic systems have been developed that utilize optics (e.g., lenticular systems, parallax barrier, mirror systems, etc.) to present the left perspective images to the left eye and the right perspective images to the right eye without the need for glasses. Such systems are costly and suffer from various technical problems such as limited depth of field, low brightness, and constrained view regions (i.e., the observer(s) are required to be located in limited viewing area(s) relative to the display).
Emagin Corp. of Hopewell Junction, N.Y. has developed a stereoscopic display system that employs two microdisplays. Each microdisplay emits light from pixels that employs organic light emitting diodes (OLEDs). Such OLED-based microdisplays are advantageous in that they provide good resolution, high contrast ratio, and sufficient brightness for near-eye applications. They are also compactness and lightweight, provide for emissive display such that no backlight or other external light source is required, and also consume less power than displays that employ external light sources. Disadvantageously, the EMagin system employs two OLED-based pixel arrays that are supported near the eyes. One of the OLED-based pixel arrays provides image formation for the left eye, while the other OLED-based pixel array provides image formation for the right eye. Because it uses two separate OLED-based pixel arrays and associated drive circuitry, the EMagin display system is costly.
Page flipping stereoscopic display systems are typically realized with a cathode ray tube (CRT) display that is adapted to operate in a progressive scan mode that alternately displays a left perspective image and a right perspective image. Such systems provide adequate performance but are limited by their screen size, weight and power consumption. With this in mind, users have attempted to employ the prior art page flipping stereoscopic display methodologies to active-matrix liquid-crystal display (LCD) panels. Such panels advantageously provide for increased screen size and significant reductions in weight. However, the backlights (or other external light sources used by such LCD panels) have limited power efficiency. Moreover, when used for page flipping stereoscopic viewing, the line-based update mechanisms employed by LCD panels cause significant cross-frame image interference where the pixels from a left perspective image are displayed concurrently with pixels from a right perspective image as shown in FIG. 1. Such interference degrades the image quality and limits the commercial acceptability of page-flipping LCD-based stereoscopic display systems. LCD-based system. These limitations are also applicable to page-flipping OLED-based stereoscopic display systems.